DE102023201711A1 - Capacitive proximity and/or touch switch - Google Patents

Abstract

The present invention relates to a capacitive proximity and/or touch switch (1) with a compression spring (2), wherein the compression spring (2) is arranged between an electrically insulating cover plate (6) and a carrier plate (8) arranged at a distance from the latter and is elastically deformable in the direction of the distance. The compression spring (2) rests with its upper end (28) on the underside (5) of the cover plate (6) and defines a sensor surface (15) there. The compression spring (2) is connected by its lower end (22) to an electrically conductive contact (9) of the carrier plate (8), wherein the compression spring (2) is a compression spring (2) wound from an elongated body and is electrically conductive, wherein an insulating layer (27) is formed between the compression spring (2) of the capacitive proximity and/or touch switch (1) and the electrically insulating cover plate (6), wherein the insulating layer (27) is arranged substantially at a distance from the electrically insulating cover plate (6).

Description

The invention relates to a capacitive proximity and/or touch switch according to claim 1.

In many electrical devices, especially in household appliances such as stoves, hobs, microwaves, dishwashers, laundry care devices and the like, touch switches are increasingly being used which trigger a specific switching process when a user simply touches them. In the case of a capacitive touch switch, a capacitive sensor element together with the user's finger forms a capacitance via a touch field acting as a dielectric, which is variable according to the actuation of the touch switch, i.e. the touching or non-touching of a touch field assigned to the capacitive sensor element. The change in the capacitance of the capacitive sensor element due to a touch by the user has a corresponding effect on an output signal of the sensor circuit, which is evaluated by a connected evaluation circuit as an actuation of the capacitive touch switch. A capacitive touch switch of this type is known, for example, from DE 32 45 803 A1 known.

In the EN 10 2007 050 654 A1 a capacitive touch switch for a control panel of an electrical household appliance is described, wherein the capacitive touch switch has a panel, a sensor surface arranged in the panel, a circuit board arranged at a distance behind the panel, and a capacitive sensor element arranged between the panel and the circuit board, in electrically conductive contact with the circuit board and associated with the sensor surface in the panel at a distance from the sensor surface. In addition, the sensor surface is formed by a plate made of a metallic material and a non-conductive insulating body is arranged between the plate and the capacitive sensor element.

It is common in conventional capacitive touch switches to use a metallized plastic surface, a plastic surface with a metallization on the side facing the sensor element, a plastic surface with a metal plate on the side facing the sensor element, or the like for the sensor surface of the control panel which is touched by the user to operate the capacitive touch switch.

In the EP 2 341 624 A1 A further capacitive touch switch is described, wherein the capacitive touch switch has a capacitive sensor element in the form of an electrically conductive hollow body which extends from a carrier plate in the direction of an electrically insulating cover plate arranged at a distance from the latter. In addition, a guide body made of an electrically insulating material is provided which extends from the cover plate into the hollow space.

In the EP 1 797 641 B1 is a capacitive proximity and/or touch switch, with an electrically conductive body which is arranged between an electrically insulating cover plate and a carrier plate arranged at a distance from the latter and is elastically deformable in the direction of the spacing, wherein the electrically conductive body rests with its upper end on the underside of the cover plate and forms a sensor surface there, and wherein the electrically conductive body is connected with its lower end to an electrically conductive contact of the carrier plate.

It is an object of the present invention to provide a capacitive touch switch which provides a more user-friendly operation and advances the state of the art to make it even safer.

The object of the invention is achieved by a capacitive proximity and/or touch switch according to claim 1. Further advantageous embodiments of the invention are specified in the subclaims as well as in the description and the drawings.

According to one aspect of the invention, the object of the invention is achieved by a capacitive proximity and/or touch switch, wherein the capacitive proximity and/or touch switch comprises a compression spring which is arranged between an electrically insulating cover plate and a carrier plate arranged at a distance from the latter and is elastically deformable in the direction of the distance. The compression spring is arranged with its upper end in the region of an underside of the cover plate and defines a sensor surface there, wherein the compression spring is connected with its lower end to an electrically conductive contact of the carrier plate. The compression spring is a compression spring wound from an elongated body and is electrically conductive, wherein an insulation layer is formed between the compression spring of the capacitive proximity and/or touch switch and the electrically insulating cover plate, wherein the insulation layer rests at least partially on the underside of the electrically insulating cover plate by means of a force generated by the compression spring.

The insulation layer can be used to provide electrical insulation between the cover plate and the compression spring, so that there is electrical separation between the cover plate and the compression spring. Furthermore, the heat resistance or thermal stability or heat resistance of the electrically insulating cover plate is increased. This makes the capacitive proximity and/or touch switch even safer against the transmission of electrical voltage and heat transfer.

According to an alternative embodiment of the invention, the object of the invention is achieved by a capacitive proximity and/or touch switch, wherein the capacitive proximity and/or touch switch comprises a compression spring which is arranged between an electrically insulating cover plate and a carrier plate arranged at a distance from the latter and is elastically deformable in the direction of the distance. The compression spring is arranged with its upper end in the region of an underside of the cover plate and defines a sensor surface there, wherein the compression spring is connected with its lower end to an electrically conductive contact of the carrier plate. The compression spring is a compression spring wound from an elongated body and is electrically conductive, wherein an insulation layer is formed between the compression spring of the capacitive proximity and/or touch switch and the electrically insulating cover plate, wherein the insulation layer is arranged substantially at a distance from the electrically insulating cover plate.

By spacing the compression spring at least partially from the electrically insulating cover plate, particularly effective electrical insulation and heat resistance of the electrically insulating cover plate can be provided. It is also conceivable that the compression spring, due to its inherent stress and/or prestress or by means of a force generated by the compression spring, leads to the insulation layer being arranged at a distance from the electrically insulating cover plate, but the distance between the electrically insulating cover plate and the insulation layer is preferably between 0.1 µm and 1 cm.

A capacitive proximity and/or touch switch detects a touch on a surface of a plate assigned to the capacitive proximity and/or touch switch. Capacitive touchscreens and/or proximity and/or touch switches determine the position of the touch by changing an electrical field. This makes it possible to determine exactly where the touch took place. A capacitive sensor is a sensor that works based on the change in the electrical capacitance of an individual capacitor or a capacitor system. A dielectric is formed between the electrically insulating cover plate and the compression spring, which is variable and reacts to touches on the cover plate. By introducing insulation into a dielectric, in the present invention the insulation layer, into the capacitive proximity and/or touch switch or between the electrically conductive compression spring and the electrically insulating cover plate, it is additionally ensured that a heat resistance or a heat resistance or heat resistance of the electrically insulating cover plate is increased, so that deformation of the electrically insulating cover plate is counteracted.

The insulation layer ensures that the capacitive proximity and/or touch switch still recognizes whether a touch field to which the capacitive proximity and/or touch switch is assigned is touched or not. The area in which the compression spring rests on the insulation layer is referred to as the contact surface. The insulation layer is arranged between the compression spring and the electrically insulating cover plate, or the insulation layer rests on the electrically insulating cover plate at least in sections. The compression spring presses the insulation layer onto the underside of the electrically insulating cover plate through its own stress and/or prestress and/or by means of a force in the area of the contact surfaces or presses the insulation layer towards the underside of the electrically insulating cover plate.

The capacitive proximity and/or touch switch is intended for a household appliance. In particular, the capacitive proximity and/or touch switch is intended for a stove and/or oven and/or steamer and/or microwave and/or for a dishwasher and/or for a refrigerator. The capacitive proximity and/or touch switch is particularly preferably intended for a laundry treatment appliance such as a washing machine, washer-dryer and/or tumble dryer.

Preferably, the insulation layer is designed as a film and/or an adhesive tape, in particular a double-sided adhesive tape. A film and/or an adhesive tape are very thin components that can be easily integrated into an existing concept, here a capacitive proximity and/or touch switch, without any spatial changes to the component or the capacitive proximity and/or touch switches. Furthermore, a film and/or an adhesive tape, even a double-sided adhesive tape, is inexpensive to purchase and easy to process in production. The insulation layer is made from a single piece and can easily be adapted to different required sizes.

The insulation layer is designed as a flexible insulation layer that is bendable or adaptable. Furthermore, the insulation layer is held in position in the area of the contact surfaces by the compression springs so that there is electrical insulation between the compression spring and the electrically insulating cover plate. The insulation layer is tensioned in the area of the contact surfaces and is thus held in position.

Advantageously, at least one spacing element is arranged between the insulation layer and the electrically insulating cover plate. This prevents direct contact between the entire insulation layer and the electrically insulating cover plate.

The at least one spacing element is preferably arranged on the electrically insulating cover plate. With this configuration, it can be achieved that in an installed state of the insulation layer, a distance from the insulation layer to the electrically insulating cover plate is at least partially present.

In a preferred embodiment, the at least one spacing element is advantageously connected to the electrically insulating cover plate in a material-locking manner. A material-locking connection includes, among other things, gluing or welding or a hot riveting process or a hot riveting process.

A material-fit connection is cost-effective, can be used in the tightest of spaces and essentially requires no additional installation space. Furthermore, a material-fit connection between two components can be easily integrated into a manufacturing process and can be carried out fully automatically.

In a particularly preferred embodiment, the at least one spacing element is integrally connected to the electrically insulating cover plate and the insulation layer.

The at least one spacer element can be easily and firmly connected to the electrically insulating cover plate and the insulation layer. By bonding these components together, little installation space is required and the connection remains essentially invisible.

In a further embodiment, the at least one spacing element is arranged on a panel component, wherein the electrically insulating cover plate is connected to the panel component.

When arranging the at least one spacing element on the panel component, it can be ensured that an electrically insulating cover plate is provided entirely for display purposes and/or operating purposes, in particular for the capacitive proximity and/or touch switch. Furthermore, it is also conceivable that a smaller electrically insulating cover plate can be used during installation. An electrically insulating cover plate can be, for example, a display element and/or a display.

Preferably, the at least one spacing element is integrally connected to the panel component. This ensures that connecting the at least one spacing element to the panel component requires little space and can be carried out in a way that is essentially invisible to a user.

The compression spring preferably has at least two turns at the upper end, with which the compression spring rests on the underside of the electrically insulating cover plate, wherein the turns lie spirally one inside the other so that a winding plate is formed, and that the winding plate with its turns forms the sensor surface, wherein at least the winding plate at least partially has the insulation layer.

The compression spring has at least two coils at its upper end, which are arranged in a spiral shape in one plane. These spirally arranged coils form a coil plate at the upper end of the compression spring, which rests against the underside of the cover plate. This coil plate is so elastic in itself that unevenness on the underside of the cover plate can be easily compensated for within the surface of the coil plate.

The insulation layer advantageously lies against the winding plate of the compression spring at least in sections. This can prevent electrical transmission from the compression spring to the electrically insulating cover plate. Furthermore, heat transfer from the compression spring to the electrically insulating cover plate can at least be reduced or even prevented.

The compression spring is preferably conical at least in an upper part and/or lower part, so that the compression spring has coils with different coil diameters. This has the advantage that, under compression stress, several coils can lie spirally in one plane and in this way a plate can only form when the compression spring is under compression stress. It is therefore not necessary to form the compression spring, particularly at its upper end, with a coil plate from the outset, but the coil plate forms automatically as soon as the compression spring is mounted under compression stress between the cover plate and the carrier plate.

The compression spring is expediently cylindrically shaped at least in a partial area, which prevents the compression spring from buckling in this partial area as soon as the compression spring is put under pressure during assembly between the carrier plate and the cover plate.

According to a preferred embodiment, in the upper part and/or lower part between at least two adjacent turns there is an axial distance in the direction of the axial spring extension, which lies in the range between zero and a cross-sectional area dimension of the elongated body in the direction of the axial spring extension, and a radial distance in the direction of the radial spring extension, which lies in the range between one and one and a half times the cross-sectional area dimension of the elongated body in the direction of the radial spring extension. The distance is determined between the middle cores of the turns, for example the center axes of the elongated body. Due to these closely spaced turns, which are arranged in particular at the upper or lower end of the compression spring, the snagging of several similar compression springs with one another during an automated assembly process of the carrier plates is prevented or reduced, since the distance between two turns is smaller than the corresponding dimension of the elongated body.

Preferably, the cylindrical portion has a lower portion at least at one of its ends in which there is an axial distance in the direction of the axial spring extension between at least two consecutive turns, which is smaller than two cross-sectional area dimensions of the elongated body in the direction of the axial spring extension. Here too, the distance is determined between the central cores of the two adjacent turns. These closely spaced turns can form a guide cylinder for a loading tool, so that the carrier plate can be automatically loaded with one or more compression springs.

In particular, the lower part area is arranged at one end of the cylindrical section, which is followed by an area with a smaller coil diameter or which is an end section of the compression spring itself. Due to these closely spaced coils, the snagging of several similar compression springs with one another is prevented or reduced during an automated assembly process of the carrier plates, since the distance between two coils is smaller than the corresponding dimension of the elongated body.

According to a preferred embodiment, the compression spring is cylindrically shaped in a first partial region and in a second partial region such that the first partial region has a different winding diameter from the second partial region, and that a conically shaped transition region is arranged between the first partial region and the second partial region.

When the compression spring is subjected to maximum pressure, the two sections can thus slide into one another, so that the section with the smaller coil diameter comes to lie with at least part of its axial extent within the section with the larger coil diameter. The spring travel of the compression spring achieved in this way is longer than a spring travel defined by the coils being evenly positioned against one another, so that the range of distances between the carrier plate and cover plate in which the compression spring can be used is correspondingly increased. This means that when manufacturing proximity or touch switches according to the invention, fewer different types of compression spring have to be produced or kept in stock, which reduces manufacturing costs.

The compression spring preferably has a position and/or rotation lock at its lower end, which is formed in particular by a molded-on soldering lug and/or a molded-on soldering pin. In this way, the compression spring can be soldered with its lower end in a simple manner to the electrically conductive contact of the carrier plate.

Advantageously, the compression spring has at least one on the carrier plate. The compression spring is electrically connected to the electrically conductive contact at at least three locations, particularly with its lower coil. This has the advantage that the compression spring can assume a stable position on the carrier plate for a soldering process. In this way, a mechanically stress-free solder connection can be achieved and, secondly, the lower coils can be soldered to the carrier plate in the form of an SMD solder connection. This makes it possible to easily automate the assembly of the carrier plate with one or more compression springs designed in this way. In particular, the compression spring has at least two coils at its lower ends, which lie spirally in one plane. An increasing number of such coils increases the wetting surface of the compression spring, which is wetted with solder paste during the soldering process, so that the stability of the compression spring on the carrier plate during the soldering process is increased.

In a preferred embodiment, a light element, such as an LED, a light bulb or a light guide, is arranged on the carrier plate within an area defined by the sensor surface, in particular within the compression spring. This light element can be used to mark the sensor surface or to signal various switching states of the proximity and/or touch switch.

• 1 zeigt in einer schematischen Schnittansicht einen beispielhaften kapazitiven Annäherungs- und/oder Berührungsschalter;
• 2 zeigt in einer schematischen Seitenansicht eine erste Ausführungsform einer Druckfeder an sich ohne Isolationsschicht;
• 3 zeigt in einer schematischen Seitenansicht eine zweite Ausführungsform einer Druckfeder an sich ohne Isolationsschicht;
• 4 zeigt in einer schematischen Seitenansicht eine dritte Ausführungsform einer Druckfeder an sich ohne Isolationsschicht;
• 5a zeigt schematisch eine erste Ausführungsform eines kapazitiven Annäherungs- und/oder Berührungsschalters mit einer Isolationsschicht;
• 5b zeigt schematisch eine weitere Ausführungsform eines kapazitiven Annäherungs- und/oder Berührungsschalters mit einer Isolationsschicht;
• 5c zeigt schematisch eine weitere Ausführungsform eines kapazitiven Annäherungs- und/oder Berührungsschalters mit einer Isolationsschicht;
• 5d zeigt schematisch eine alternative Ausführungsform eines kapazitiven Annäherungs- und/oder Berührungsschalters mit einer Isolationsschicht.

Further features and advantages of the present invention will become apparent from the following description with reference to the drawings.

• 1 shows a schematic sectional view of an exemplary capacitive proximity and/or touch switch;
• 2 shows in a schematic side view a first embodiment of a compression spring without an insulating layer;
• 3 shows in a schematic side view a second embodiment of a compression spring without an insulating layer;
• 4 shows in a schematic side view a third embodiment of a compression spring without an insulating layer;
• 5a shows schematically a first embodiment of a capacitive proximity and/or touch switch with an insulation layer;
• 5b shows schematically another embodiment of a capacitive proximity and/or touch switch with an insulation layer;
• 5c shows schematically another embodiment of a capacitive proximity and/or touch switch with an insulation layer;
• 5d shows schematically an alternative embodiment of a capacitive proximity and/or touch switch with an insulation layer.

Before going into the drawings in more detail, it should be noted that corresponding or identical elements or individual parts in the various embodiments of the capacitive proximity and/or touch switch according to the invention are designated by the same reference numerals in all drawing figures.

In 1 an example of a proximity and/or touch switch is shown in a schematic sectional view. The switch 1 contains a wound compression spring 2 as an electrically conductive body, which is preferably made of spring wire. This spring wire preferably has a round cross-section 3, although other cross-sectional shapes are also possible, such as an oval or a polygon. The compression spring 2 has a plurality of turns 4 at its upper end 28, which rest against an underside 5 of a curved, electrically insulating cover plate 6 in a form-fitting manner and under a compressive stress. These turns lie spirally inside one another and in this way form a flat winding plate 7, which elastically adapts to the curvature of the cover plate 6 under the spring tension. The cover plate 6 can consist of a dielectric, such as glass, glass ceramic or plastic. A carrier plate 8 with an electrically conductive contact surface 9 facing the underside 5 of the cover plate 6 is arranged at a distance from the cover plate 6. The carrier plate 8 can be a plastic plate which has the aforementioned contact surface 9 on at least one of its plate sides and optionally conductor tracks via which the contact surface 9 is electrically connected to an evaluation circuit (not shown). The compression spring 2 has a lower winding 10 at its lower end, with which it lies flat on the contact surface 9 of the carrier plate 8. A soldering lug 11 is formed on the lower end of the compression spring 2 as a position and/or rotation lock, which protrudes through a hole 12 in the carrier plate 8. The soldering lug 11 is connected to the carrier plate 8 by a wave solder connection 13 and the lower winding 10 by an SMD solder connection 14. Between the lower winding 10 and the winding plate 7, the compression spring 2 is conical in the shape of a truncated cone, with the winding diameter decreasing from the lower winding 10 to the winding plate 7.

The upper windings 4 of the winding plate 7, which are in contact with the underside 5 of the cover plate, define a sensor surface 15 which is delimited by an outer winding 16 of the upper windings 4. In particular, the outer winding 16 lies completely against the underside 5 of the cover plate 6. If an element, such as a finger, which carries a potential different from the potential of the contact surface 9 of the carrier plate 8, in particular ground potential, is brought closer to and/or brought into contact with a surface area 17 of the cover plate 6 opposite the sensor surface 15, this causes a change in capacitance of a capacitor consisting of the element in question or the finger, the cover plate and the sensor surface 15. Since the sensor surface 15 is electrically conductively connected to the contact surface 9 of the carrier plate 8 and this in turn is connected to the evaluation circuit, the change in capacitance can be determined and evaluated by the evaluation circuit. Furthermore, a light source (not shown), such as an LED, can be provided on the carrier plate 8 in the area inside the compression spring 2 in order to mark the sensor surface 15 or to signal different switching states of the switch 1. An electrically conductive layer (not shown) can also be applied to the surface of the cover plate 6 in order to generate a uniform potential distribution in the surface area 17 opposite the sensor surface 15 when touched or approached. In particular, this electrically conductive layer, the shape of which can be different from that of the sensor surface 15, can also extend beyond the surface area 17 so that the area in which the proximity or touch switch can be actuated is increased. This electrically conductive layer can in turn be coated with a dielectric protective layer (not shown) in order to prevent damage to the electrically conductive layer and/or to mark the position of the proximity or touch switch.

In 2 a schematic side view of a first embodiment of the compression spring 2 according to the invention is shown. The helically wound compression spring 2 has a lower part 18 in the form of a truncated cone, in which the winding diameter decreases from the lower winding 10 upwards to a limit winding 19. This is followed by an upper part 20, also in the form of a truncated cone, in which the winding diameter now increases again from the limit winding 19 to the uppermost winding 4a. If the compression spring 2 is placed under compressive stress between the cover plate 6 and the carrier plate 8 according to 1 assembled, the upper part 20 is compressed in such a way that the uppermost windings 4a, 4b and 4c slide into each other in a spiral manner. In this way, the winding plate 7 is correspondingly 1 formed in which the upper windings 4a, 4b and 4c are in positive contact with the underside 5 of the cover plate. Alternatively, it is also possible to form the winding plate 7 directly onto the limit winding 19 when the compression spring 2 is not yet under compressive stress.

In 3 a schematic side view of a second embodiment of the compression spring 2 according to the invention is shown. In this case, the helically wound compression spring 2 has a lower section 21 in the form of a cylinder, in which the winding diameter remains the same from the lower winding 10 to the limit winding 19. This is followed by the upper section 20 in the form of a truncated cone, in which, however, the winding diameter now increases from the limit winding 19 to the uppermost winding 4a, so that when the compression spring 2 is mounted between the cover plate 6 and the carrier plate 8 under compressive stress, the winding plate 7 can be formed again.

In 4 a schematic side view of an embodiment of a compression spring 2 is shown without an insulating layer.

In this case, the helically wound compression spring 2 has two lower turns 10, 10' at its lower end 22, which lie spirally in one plane and in this way ensure that the compression spring 2 rests stably on the carrier plate 8. These lower turns 10, 10' are wetted with solder paste during the soldering process and soldered to the carrier plate, which can in particular be a printed circuit board, for example in the form of an SMD solder connection. Starting from the lower turn 10, the compression spring 2 has two lower turns 10, 10', analogously to 3 a first partial area 21' in the form of a cylinder, in which the winding diameter remains the same from the lower winding 10 to a first limit winding 19'. This is followed by a transition area 23 in the form of a truncated cone, in which the winding diameter now decreases from the limit winding 19' to a second limit winding 19". The limit winding 19" is followed by a second partial area 24 in the form of a cylinder, in which the winding diameter remains the same from the second limit winding 19" to a third limit winding 19'''. The winding diameter of the second partial area 24 is thus smaller than the winding diameter of the first partial area 21'. The second partial area 24 is followed by a transition area 23 in the form of a truncated cone, in which the winding diameter decreases from the limit winding 19' to a second limit winding 19". 2 the upper part 20 in the form of a truncated cone, in which the winding diameter from the limit turn 19''' to the uppermost turn 4a and which forms the turn plate 7 when the compression spring 2 is under pressure.

The windings 4a to 4g of the upper part 20 are wound so tightly that between any two adjacent windings there is an axial distance A in the direction of the axial spring extension of half a spring wire diameter D and a radial distance R in the direction of the radial spring extension of a whole spring wire diameter D. The distance between two windings is measured from their centers. When the compression spring 2 is under compressive stress, a closed winding plate 7 is thus formed, in which adjacent windings of the windings 4a to 4g touch each other. The first cylindrical portion 21' has at its lower end a first lower portion 25 with three turns 26a, 26b and 26c and at its upper end a second lower portion 25' with three turns 26d, 26e and 26f, each of which is wound so tightly that between any two adjacent turns there is an axial distance A' in the direction of the axial spring extension of a spring wire diameter D, i.e. the adjacent turns 26a and 26b, 26b and 26c, 26d and 26e, 26e and 26f each touch one another, so that in the lower portions 25 and 25' the compression spring 2 has no spring effect. These closely spaced turns 4a to 4g, 26a to 26c and 26d to 26f prevent similar compression springs 2 from getting caught in one another during an automated assembly process, since the distance between any two adjacent turns of the turns 4a to 4g, 26a to 26c and 26d to 26f is smaller than the spring wire diameter D.

The second cylindrical section 24 has at its upper end a third lower section 25" with three windings 26g, 26h and 26i, which are also wound so tightly that between every two adjacent windings there is an axial distance A' in the direction of the axial spring extension of a spring wire diameter D, i.e. the adjacent windings 26g and 26h or 26h and 26i touch each other, so that in the third lower section 25" the compression spring 2 has no spring effect. These closely adjacent windings 26g to 26i form a guide cylinder for an assembly tool, so that the carrier plate can be automatically equipped with one or more compression springs 2.

Overall, the compression spring 2 is wound in one piece from metallic spring wire. However, it is also possible to manufacture the compression spring 2 from other electrically conductive materials, such as electrically conductive plastic or plastic with a metallic core, in the form of a plastic injection molding. The compression spring 2 preferably has circular windings, but various other shapes are also possible, such as ovals, ellipses or polygons.

In the 5a to 5c An embodiment of a capacitive proximity and/or touch switch 1 is shown schematically. In 5d An alternative embodiment of a capacitive proximity and/or touch switch 1a is shown schematically.

The 5a to 5d The schematically illustrated compression springs 2, which are arranged on a carrier plate 8, have the features and properties of one of the compression springs 2, which in the respective embodiments in the 2 until 4 shown or described above. Each of the elements shown in the embodiments in the 5a to 5d The schematically shown capacitive proximity and/or touch switch 1 has an insulation layer 27. In the present embodiments, three compression springs 2 are arranged on the carrier plate 8 by way of example. However, it is also conceivable that fewer than three compression springs 2 or more than three compression springs 2 are arranged on the carrier plate 8.

The insulation layer 27 has contact surfaces 28, wherein the compression springs 2 at least partially touch the insulation layer 27 or at least partially rest against the contact surfaces 28 of the insulation layer 27. The insulation layer 27 has at least one first section 29, which is formed in the region of the contact surface 28. Furthermore, the insulation layer 27 has at least one second section 30, which is formed outside the first section 29. The at least one second section 30 remains untouched by the compression spring 2 or is contactless, or the at least one second section 30 is not touched by the compression spring 2. In the embodiments in the 5a to 5c the at least one second section 30 of the insulation layer 27 is spaced from the underside 5 of the electrically insulating cover plate 6. In the embodiment in 5d the first section 29 as well as the second section 30 are spaced from the underside 5 of the electrically insulating cover plate 6.

In the examples in 5a to 5c the insulation layer 27 is shown as square for illustration purposes. The insulation layer 27 is flexible. The insulation layer 27 is a flexible film or a flexible adhesive tape that is bendable. As a result, the insulation layer 27 conforms to the contour defined by the compression spring 2 and the at least one spacing element 33. ture. The insulation layer 27 has bulges 31 in the region of the contact surfaces 28. The insulation layer 27 has in particular a wave-like structure or the insulation layer 27 is wave-shaped, wherein the at least one first section 29 represents a bulge 31 or an elevation of the insulation layer 27.

Regarding the 5a to 5c This means that the insulation layer 27 is curved in the area of the contact surfaces 28 or in at least one first section, i.e. in the area of the compression spring 2, and rests at least partially against the underside 5 of the electrically insulating cover plate 6. Outside the contact surfaces 28 or in the at least one second section, i.e. in the areas in which the insulation layer 27 is spaced apart from the compression spring 2, the insulation layer 27 is spaced apart from the underside 5 of the electrically insulating cover plate 6.

In 5a an embodiment of a capacitive proximity and/or touch switch 1 is shown schematically. The capacitive proximity and/or touch switch 1 comprises a carrier plate 8 on which at least one compression spring 2 is arranged.

At an upper end 32 of the compression springs 2, the compression springs 2 rest on the insulation layer 27 on a first side of the insulation layer 27. The insulation layer 27 is preferably designed as a film, in particular as an adhesive film and/or as an adhesive tape, in particular as a double-sided adhesive tape. Furthermore, the insulation layer 27 is connected to at least one spacing element 33. The at least one spacing element 33 is arranged on a second side of the insulation layer 27, wherein the second side of the insulation layer 27 is formed opposite the first side. The at least one spacing element 33 is connected to the underside 5 of the cover plate 6 via at least one connecting element 34 or connecting means or a connecting technology. The at least one spacing element 33 is arranged on the underside 5 of the cover plate 6 in a materially bonded manner and/or is materially bonded to the underside 5 of the cover plate 6, at least in sections. This means that the at least one connecting element 34 can be designed as an adhesive and/or welded element or as an adhesive and/or welded connection. However, it is also conceivable that the spacing element 33 is arranged on the underside 5 of the cover plate 6 or is connected to the underside 5 of the cover plate 6 by means of a hot stamping process, by means of hot riveting or by means of hot caulking and/or a hot riveting process.

In the embodiment in 5b , another embodiment of a capacitive proximity and/or touch switch 1 is shown schematically.

At an upper end 32 of the compression springs 2, the compression springs 2 rest on a first side of the insulation layer 27 on the insulation layer 27. The insulation layer 27 is preferably designed as a film, in particular as an adhesive film and/or as an adhesive tape, in particular as a double-sided adhesive tape. Furthermore, the insulation layer 27 is connected to the at least one spacing element 33 via at least one connecting element 34. The at least one spacing element 33 is arranged on a second side of the insulation layer 27, wherein the second side of the insulation layer 27 is formed opposite the first side. The insulation layer 27 is preferably connected in a materially bonded manner to the at least one spacing element 33. The at least one spacing element 33 is also arranged on the underside 5 of the cover plate 6, at least in sections, in a material-locking manner and/or is also connected to the underside 5 of the cover plate 6, at least in sections, in a material-locking manner.

In the embodiment in 5c , another embodiment of a capacitive proximity and/or touch switch 1 is shown schematically.

At an upper end 32 of the compression springs 2, the compression springs 2 rest on a first side of the insulation layer 27 on the insulation layer 27. The insulation layer 27 is preferably designed as a film, in particular as an adhesive film and/or as an adhesive tape, in particular as a double-sided adhesive tape. Furthermore, the insulation layer 27 can be connected to the at least one spacing element 33 via at least one connecting element 30. The at least one spacing element 33 is arranged on a second side of the insulation layer 27, wherein the second side of the insulation layer 27 is formed opposite the first side. In the present exemplary embodiment, the insulation layer 27 at least rests on the spacing element 33. If the insulation layer 27 is designed as an adhesive tape, the insulation layer 27 can be integrally connected to the at least one spacing element 33.

The at least one spacing element 33 is in the embodiment in 5c connected to at least one panel component 35. Preferably, the at least one spacing element 33 is connected to at least one connecting element 34 with the at least one panel component 35 at least in sections. The at least one spacing element 33 is preferably connected in a materially bonded manner to the at least one panel component 35. The at least one panel component 35 can comprise an opening 36 and/or consist of several individual components. The electrically insulating cover plate 6 is arranged or accommodated in the opening 36 of the panel component 35 or the electrically insulating cover plate 6 is accommodated between the individual components of the panel component 35. This means that in the embodiment in 5c , the electrically insulating cover plate 6 or underside 5 of the electrically insulating cover plate 6 is not connected to a connecting element 34 or to the at least one spacing element 33.

The at least one spacing element 33 can be designed to be circumferential and/or consist of several parts. The at least one connecting element 34 can also be designed to be circumferential and/or be applied circumferentially to the corresponding component. The 5c The at least one cover component 35 described can also be designed to be circumferential and thus surround the electrically insulating cover plate 6, so that the electrically insulating cover plate 6 is accommodated in the cover component 35.

In the alternative embodiment in 5d , a further or alternative embodiment of a capacitive proximity and/or touch switch 1 is shown schematically.

The structure of the 5d The capacitive proximity and/or touch switch 1a shown is essentially the same as that of the 5a shown or described above. It would also be conceivable that the capacitive proximity and/or touch switch 1 5d shown alternative embodiment of one of the 5 b or 5c shown embodiment of a capacitive proximity and/or touch switch 1.

The difference from the 5d shown capacitive proximity and/or touch switch 1a to the in 5a to 5c shown capacitive proximity and/or touch switch 1 is that the insulation layer 27 is essentially spaced from the underside 5 of the electrically insulating cover plate 6. This means that the insulation layer 27 is also spaced from the electrically insulating cover plate 6 in the region of the contact surface 28. This means that the first section 29 as well as the second section 30 are spaced from the electrically insulating cover plate 6.

The insulation layer 27 in 5d can preferably be designed as a flexible film, in particular as an adhesive film and/or as an adhesive tape, in particular as a double-sided adhesive tape.

List of reference symbols

1.

Proximity and/or touch switches

1a

Proximity and/or touch switches

2.

coiled compression spring

3

Cross section of the spring wire

4

upper coils of the compression spring

5

Bottom of the cover plate

6

Cover plate

7

Winding plate

8

Carrier plate

9

electrically conductive contact surface

10

lower winding

11

Solder lug

12

Hole of the carrier plate

13

Wave soldering connection

14

SMD solder connection

15

Sensor area

16

outer winding of the upper windings

17

Surface area of the cover plate

18

lower part

19

Border winding

20

upper part

21

lower or first section

22

lower end of the compression spring

23

conical shaped transition area

24

second part

25

Lower section

26

Winding of the lower part

27

Insulation layer

28

Contact surface compression spring to insulation layer

29

First section of the insulation layer

30

Second section of the insulation layer

31

bulge

32

upper end of the compression spring

33

at least one spacing element

34

at least one connecting element

35

at least one panel component

36

Opening

A

axial distance between two turns

R

radial distance between two turns

D

Spring wire diameter

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• DE 3245803 A1 [0002]
• DE 102007050654 A1 [0003]
• EP 2341624 A1 [0005]
• EP1797641B1 [0006]

Claims (16)

Capacitive proximity and/or touch switch (1), with a compression spring (2) which is arranged between an electrically insulating cover plate (6) and a carrier plate (8) arranged at a distance from the latter and is elastically deformable in the direction of the distance, the compression spring (2) resting with its upper end (28) in the region of a lower side (5) of the electrically insulating cover plate (6) and defining a sensor surface (15) there, and the compression spring (2) being connected with its lower end (22) to an electrically conductive contact (9) of the carrier plate (8), the compression spring (2) being a compression spring (2) wound from an elongated body and being electrically conductive, characterized in that an insulating layer (27) is formed between the compression spring (2) of the capacitive proximity and/or touch switch (1) and the electrically insulating cover plate (6), the insulating layer (27) being formed by means of a spring formed by the compression spring (2) generated force rests at least partially on the underside (5) of the electrically insulating cover plate (6). Capacitive proximity and/or touch switch (1a), with a compression spring (2) which is arranged between an electrically insulating cover plate (6) and a carrier plate (8) arranged at a distance from the latter and is elastically deformable in the direction of the distance, the compression spring (2) resting with its upper end (28) in the region of a lower side (5) of the electrically insulating cover plate (6) and defining a sensor surface (15) there, and the compression spring (2) being connected with its lower end (22) to an electrically conductive contact (9) of the carrier plate (8), the compression spring (2) being a compression spring (2) wound from an elongated body and being electrically conductive, characterized in that an insulating layer (27) is formed between the compression spring (2) of the capacitive proximity and/or touch switch (1) and the electrically insulating cover plate (6), the insulating layer (27) being substantially spaced from the electrically insulating cover plate (6). Capacitive proximity and/or touch switch (1, 1a) according to Claim 1 or 2 , characterized in that the insulation layer (27) is designed as a film and/or an adhesive tape, in particular a double-sided adhesive tape. Capacitive proximity and/or touch switch (1, 1a) according to one of the preceding claims, characterized in that at least one spacing element (33) is arranged between the insulation layer (27) and the electrically insulating cover plate (6). Capacitive proximity and/or touch switch (1, 1a) according to Claim 4 , characterized in that the at least one spacing element (33) is arranged on the electrically insulating cover plate (6). Capacitive proximity and/or touch switch (1, 1a) according to Claim 4 or 5 , characterized in that the at least one spacing element (33) is integrally connected to the electrically insulating cover plate (6). Capacitive proximity and/or touch switch (1, 1a) according to Claim 4 or 5 , characterized in that the at least one spacing element (33) is materially connected to the electrically insulating cover plate (6) and the insulation layer (27). Capacitive proximity and/or touch switch (1, 1a) according to Claim 4 , characterized in that the at least one spacing element (33) is arranged on a panel component (35), wherein the electrically insulating cover plate (6) is connected to the panel component (35). Capacitive proximity and/or touch switch (1, 1a) according to Claim 8 , characterized in that the at least one spacing element (33) is connected to the panel component (35). Capacitive proximity and/or touch switch (1, 1a) according to one of the preceding claims, characterized in that the compression spring (2) has at least two turns (4) at the upper end (28), with which the compression spring (2) rests on the underside (5) of the electrically insulating cover plate (6), that the turns (4) lie spirally one inside the other so that a turn plate (7) is formed, and that the turn plate (7) with its turns (4) forms the sensor surface (15), wherein at least the turn plate (7) at least partially has the insulation layer (27). Capacitive proximity and/or touch switch (1, 1a) according to Claim 10 , characterized in that the insulation layer rests against the winding plate (7) of the compression spring (2) at least in sections. Capacitive proximity and/or touch switch (1, 1a) according to one of the Claims 9 or 10 , characterized in that the compression spring (2) is conical at least in an upper partial region (20) and/or lower partial region (18) such that the compression spring (2) has windings (4a, 4b, 4c) with different winding diameters. Capacitive proximity and/or touch switch (1, 1a) according to one of the preceding claims, characterized in that the compression spring (2) is cylindrically shaped at least in a partial region (21, 21', 24) and the cylindrical partial region (21', 24) has a lower partial region (25, 25', 25") at least at one of its ends in which there is an axial distance (A') in the direction of the axial spring extension between at least two consecutive turns (26a-26g), which is smaller than two cross-sectional area dimensions (D) of the elongated body in the direction of the axial spring extension, wherein the lower partial region (25, 25') is arranged at one end of the cylindrical partial section (21'), to which an area (23) with a smaller winding diameter adjoins or which is an end section (25) of the compression spring (2) itself. Capacitive proximity and/or touch switch (1, 1a) according to Claim 12 , characterized in that the compression spring (2) is cylindrically shaped in a first partial region (21') and in a second partial region (24) such that the first partial region (21') has a different winding diameter from the second partial region (24), and that a conically shaped transition region (23) is arranged between the first partial region (21') and the second partial region (24). Capacitive proximity and/or touch switch (1, 1a) according to one of the preceding claims, characterized in that the compression spring (2) has a position and/or rotation lock (11, 13, 14) at its lower end (22), wherein the position and/or rotation lock (11, 13, 14) is formed by a molded-on soldering lug (11) and/or a molded-on soldering pin. Compression spring (2) for a capacitive proximity and/or touch switch (1, 1a) according to one of the Claims 1 until 15 .

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